Field of the Invention
The present invention relates to method for installing of a wet mateable connection assembly for undersea energy applications.
In particular the present invention especially refers to a wet mateable connection assembly for electrical and/or optical cables.
In particular, the present invention especially refers to a wet mateable connection assembly for medium and high voltage electrical cables. Typically, by medium voltage cables we mean cables suitable for more than 1 kV and up to about 30 KV, and for high voltage cables we mean cables suitable for operating above about 30 kV.
Description of the Related Art
The oceanic/undersea energy generation is growing at a fast speed and in this field the technologies used to generate energy are dominantly “wind mills” but wave and tidal generators are showing some promising results.
The wind mills are generally built with fixed bottom structures and inter array cables are used to go from one turbine to the next and to the shore.
In order to connect the wind mills or similar apparatus to an electric network, cables are used wherein the cable connections may be “dry mate”, i.e. the ends of the cables coming from the wind mills and of the cables of the electric network or of intermediate stations are connected together (i.e. are mated, or unmated, by means of appropriate connectors) in a dry environment (e.g on the shore or on a suitable floating vessel or ship), to avoid the presence of water at the connector interface, which may produce partial discharges and the consequent cable faults in the presence of electrical field, and subsequently laid down underwater.
Cable hubs and/or cable substations can be used for connecting two or more underwater cables of an electric network. In these cases, and especially in places where water depths exceed 40 m depth, the dry mating is more cumbersome because it implies retrieving from underwater, for example to a ship, a sunken hub or substation having a significant weight.
In similar circumstances, the dry mating is often unpractical and generally economically disadvantageous.
In offshore windmills and other submarine applications, wet mateable connection assemblies are known.
The wet mateable connection assemblies are configured to allow the cable connection to be realized directly undersea.
Known wet mateable connection assemblies utilize two connectors attached to the relevant cable ends, to be mated together. As disclosed, for example, by U.S. Pat. No. 6,736,545, such connectors generally comprise a plug unit containing one or more contact probes and a receptacle unit containing an equivalent number of contacts or junctions for engagement with the contact probes, which extend into the receptacle unit when the units are connected to each other. Typically, the probes enter the container via one or more openings which are sealed when the connector elements are separated.
The installation of a wet mateable connection assembly on the seabed generally comprises:                providing on the seabed a first connector case, connected to a submersed cable;        providing a second connector case, connected to a submersible cable, in a position close to the first connector case,        moving one of the connector cases in order to put in contact the two connector cases.        
The moving step comprises positioning one case in alignment with the other. This step is typically performed by operators or, when the depth exceeds the safety requirements, by a remotely operated vehicle (ROV).